Non-silver color light sensitive photographic elements and method of using same



United States Patent 3,192,645 NON-SILVER COLQR LIGHT SENSITIVE PHOTO- ggtAPl-HC ELEMENTS AND METHOD OF USING ME Charles R. Barr, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Feb. 1, 1963, Ser. No. 255,689 19 Claims. (Cl. 96-48) This invention is related to direct image-forming photographic elements, and more particularly to non-silver photographic elements and their use to produce direct positive photographic dye images.

Dye image-forming photographic elements are known which contain incorporated dye-forming couplers in lightsensitive silver halide emulsion layers. Usually these elements are multilayer multicolor and contain a redsensitive layer with a cyan image-forming coupler, a green-sensitive layer with a magenta image-forming coupler, and a blue-sensitive layer with a yellow imageforming coupler coated on a transparent support in the order given or in some other order. After exposure to an original image, such an element is processed to produce a dye negative image reproduction of the original by the following steps: Color development to produce the silver and dye images (negative), acid stop bath, hardener, wash, ferricyanide bleach, wash, hypo fix, wash and dry. The multicolor negative thus produced is then printed on print material which has a white opaque support having coated on it a red-sensitive layer, a green-sensitive layer, and a blue-sensitive layer as described above. The image exposed print material is given a process similar to that used for the negative material to produce the multicolor positive image reproduction of the original.

In the well known multilayer multicolor photographic reversal elements, the diflerently sensitized layers do not contain the color-forming couplers. The couplers are included in the appropriate color developer solution. The processing of such a reversal element is even more complex than the processing of a negative positive element. Reversal process steps usually involve prehardening, washing, negative image development, washing, selective re-exposure of the red-sensitive layer, cyan image development, Washing, selective re-exposure of the bluesensitive layer, yellow image development, washing, fogging of the green-sensitive layer, magenta image development, washing, bleaching, fixing, washing and drying.

Photographic elements capable of producing direct positive photographic dye images by a simple process are desired.

It is therefore an object of my invention to provide a light-sensitive photographic element that is valuable for producing direct positive photographic dye images by simply soaking the element briefly in water or an alkaline solution, exposing it to a light image and then rinsing the exposed element in water to produce a direct positive dye image.

Another object is to provide a non-silver light-sensitive multilayer photographic element for producing multicolor direct positive dye image reproductions.

Still other objects will become evident from the following specification and claims.

'These and other objects are accomplished according to my invention by the use of my non-silver photographic elements.

My photographic element in its simplest form comprises a support having coated on it at least one light- .sensitive layer comprising a hydrophilic colloid having dispersed therein (1) an inorganic semiconductor that produces hydrogen peroxide when it is exposed toactivating light in the presence of moisture and oxygen, such that the amount of hydrogen peroxide produced is proportional to the amount of exposure and (2) a dye which contains an u-diketone group such that when said group is split by the action of hydrogen peroxide, the nondiifusing dye becomes diffusible or undergoes a change in the chromophore group (but not destruction of the chromophore), or the nonditfusing dye becomes both diifusible and undergoes a color change (but does not become colorless). The diffusible dye negative image produced by exposure of the element is either washed out of the element or is transferred to a mordanted receiving sheet and in either instance leaves a positive image in the element comprising the nondiifusing dye.

My elements may have three differently sensitized light-sensitive layers for producing the three colored images needed to produce a multicolor print.

The hydrophilic colloids used to advantage in making my light-sensitive layers can be any hydrophilic colloid suitable for suspending and coating the semiconductor and the u-diketone containing dye; these include colloids such as gelatin, polyvinyl alcohol, polyvinyl acetate, polyacrylimide, carboxymethylcellulose, etc.

Any semiconductors which produce hydrogen peroxide when irradiated with activating radiation in the presence of water and oxygen, can be used to advantage in my lightsensitive layers. Included among the useful semiconductors are materials, such as zinc oxide, titanium dioxide, cadmium sulfide, gallium nitride, cadmium selenide, etc. Usually, these materials are reduced to a particle size ranging from colloidal size up to about So. Zinc oxide is made by the French process. The other semiconductors are made by other known chemical methods.

In general, the white semiconductors, such as zinc oxide, titanium dioxide, etc., are inherently sensitive to the ultraviolet region of the spectrum, while the semiconductors that are colored are inherently sensitive to light that they absorb. These materials are sensitized to light of longer wavelengths by methods, such as are described by Thomsen in U.S. Patents 2,727,807, 2,727,808, both issued December 20, 1955, to panchromatically sensitize zinc oxide.

Included among the m-diketone dyes used to advantage in my light-sensitive elements to produce direct positive images are those represented by the formula:

wherein W represents any organic dye that has selective absorption in the visible region of the spectrum, such as an azo dye, a triphenylmethane dye, a methine dye, an in'doaniline dye, an indophenol dye, an azomethine dye and an anthraquinone dye, etc., all of which contain solubilizing groups, such as sulfonic, phosphonic, carboxylic acids, ionizable sulfonamido, hydroxyl groups, etc.; Y represents a ballast group, such as an alkyl group having from 10 to 22 carbon atoms, e.g., decyl, phenyldecyl, pentadecyl, docosyl, etc.; and n represents an integer of from O to 1.

When a dye of Formula I is treated with hydrogen peroxide, the a-diketone group splits releasing one diffusible dye molecule and a ballast group, or two diffusible dye molecules depending on the structure, e.g., whether n=1 or n=0. The splitting or cleavage of dyes of Formula I at the a-diketone group does not destroy the chromophore in the W group, for example, the azo group of an azo dye, and the diffusible dye moiety does not become colorless. The dilfusible dye moiety released by the action of hydrogen peroxide in my element is advantageously transferred to a mordanted receiving sheet by contacting the receiving sheet to my wet and image exposed element. Upon separation a dye negative image is found in the receiving sheet and a dye positive image is found in the element.

Included among the dyes of Formula I are the following representative dyes used to illustrate my invention.

DYE 1 4,4 -bis(1 zydroxy-4-naphthylazo) benzil t t H H O DYE 4 4,4-bis(1-phanyl-3-methyl-5-pyraz0lonyl-4-az0) benzil DYE 5 CzHu CH3CHZOH DYE 6 4- (4-stearoylcarbonylphenylazo) -1-naphthol I it DYE 7 4,4 '-bis(8-amin0-3,6 -disul 10-1 -hydr0xy-2 map]: thy lazo) benzil tetrasodium salt The hydrophilic dyes are added to the light-sensitive coating composition as a water solution, while the hydrophobic dyes are added as a solution in any of the waterimmiscible water-permeable high-boiling solvents and/ or auxiliary solvents.

The high-boiling solvents used to advantage include any of the high-boiling solvents, such as those listed in Mannes et al. US. Patents 2,304,939 and 2,304,940, both issued December 15, 1942; Ielley et al. US. Patent 2,322,027, issued June 15, 1943, and others. Representative solvents include dibutylphthalate, B-rnethoxyethyl phthalate, ethyl-N,N-di-n-butyl carbamate, tricresyl phosphate, trip-tert-butylphenyl phosphate, triphenyl phosphate, ditetrahydrofurfuryl succinate, tetrahydrofurfuryl benzoate, N- n-amyl phthalimide, N-n-amyl succinimide, triethylene glycol, ethylene glycol monobenzyl ether, glycol salicylate, etc.

Although my hydrophobic dyes may be dissolved in 7 the high-boiling solvents over a wide range of concentrations, they are usually used in a dye to high-boiling solvent ratio of from 1:0 to about 1:3.

Auxiliary solvents used to advantage include the low boiling or water-soluble organic solvents, such as those 4 described by Fierke et al. US. Patent 2,801,171 and Vittum et al. US. Patent 2,801,170, both issued July 30, 1957; Julian U.S. Patent 2,949,360, issued August 16, 1960, etc.

The light-sensitive coating composition used for coating my elements is made by dispersing the finely ground semiconductor and the solution of the dye in the hydrophilic colloid and intimately blending the mixture. The coating composition is coated on a wide variety of photographic emulsion supports by any of the usual coating techniques.

Typical supports used to advantage include cellulose nitrate film, cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene film, polypropylene film, and related films of resinous materials, as well as paper, glass and other materials. These materials may be clear or contain a white opaque pigment where it is desired to use the element to make color prints.

The process for making direct dye images with my elements is very simple. The element is soaked briefly in water or preferably in a water solution of an alkali having a pH of about 13, the wet element is exposed to a light image, and then rinsed in running water to remove the diifusible materials from the element, leaving the direct positive dye image in the element. As mentioned previously, the diifusible dye image (produced by the imagewise splitting of the a-diketone group in the otherwise nondiifusible dye) can be transferred if desired to a mordanted receiving sheet that is contacted with the exposed and wet photographic element before the water rinse.

Although the image in the water rinsed and dried element is relatively stable to printout, it is advantageous to treat the element with dilute acid solution (for example about 5% HCl) to dissolve and remove the semiconductor.

Any receiving sheet having a cationic mordant in the receiving layer is used to advantage for transferring the dye image. Such a receiving sheet may comprise any of the support material described previously having coated on them a hydrophilic colloid layer containing a cationic mordant, e.g., the polymers of amino guanidine derivatives of vinylmethylketone, such as described in Minsk US. Patent 2,882,156, granted April 14, 1959. Other mordants include the 2-vinylpyridine polymer, metho-ptoluene sulfonate, and similar compounds described in Sprague et al. US. Patent 2,484,430, granted October 11, 1949, and cetyltrimethylammonium bromide, etc. Particularly etfective mordanting compositions are described in copending applications of Kneckel et al. US Serial No. 211,095, filed July 19, 1962, and Bush US. Serial No. 211,094, filed July 19, 1962.

The following examples will still further illustrate my invention but it is to be understood that the invention is not to be limited to these examples.

EXAMPLE 1 A single layer coating containing polyvinyl alcohol 700 mg./ft. zinc oxide 700 mg./ft. and 4,4'-bis(1-hydroxy- 4-naphthylazo)benzil 7 mg./1':t. was coated on a cellulose acetate support from an intimate dispersion of these materials. Another coating like this but containing no zinc oxide was made on another piece of support. After drying, both coatings were soaked for two minutes in an aqueous solution of sodium hydroxide having a pH of 13, and while still wet, were exposed to a No. 2 Photollood lamp at 1 foot for three minutes through an original image. The exposed elements were washed with water. In the element containing zinc oxide a positive magenta dye image reproduction of the original was produced. No image was produced in the other element.

EXAMPLE 2 Single layer coatings were made as in Example 1 but substituting 4,4-bis(1-hydroxy 2 carboxy 4-naphthylazo)benzil 'for the dye used in Example 1. A positive magenta dye image was produced in the zinc oxide containing element by the process of Example 1. No image was produced in the absence of zinc oxide.

EXAMPLE 3 Example 1 was repeated using 4,4'-bis(l-p-sulfophenyl- 3-methyl-5-pyrazolyl-4-azo)benzil in place of the dye used in Example 1. Processing and exposure caused the orange colored dye in the zinc oxide coating to change to yellow in exposed areas thus producing an orange dye positive and a yellow dye transferable negative image. No image was produced in the element that did not contain zinc oxide.

EXAMPLE 4 Example 1 was repeated using 4,4'-bis(1-phenyl-3- methyl-5-pyrazolyl-4-azo)benzil in place of the dye used previously. The element containing zinc oxide produced a dire-ct orange dye positive and a yellow transferable negative image.

Similarly, when 1-oxo-4-{4-[N-ethyl-N-(,B-hydroxyethyl)phenyl]imino}-4'-stearoylcarbonyl-2 naphthanilide is used as the dye in a coating such as described in Example 1, a cyan dye direct positive image is produced by my process. 1

Similar results are obtained when the other semiconductors of my invention are substituted for zinc oxide.

My invention is still further described by the following description of the preparation of typical dyes of Formula I used in the examples.

DYE 1 To a slurry of 12 g. of 4,4'-diaminobenzil (J. Chem. Soc. 251 (1947)) in a mixture of 52 ml. of concentrated hydrochloric acid and 300 ml. of water was added at 0 C. with stirring over a period of /2 hour a solution of 7 g. of sodium nitrite in 20 ml. of water.

To this diazonium solution was added a solution of 14.5 g. of a-naphthol and 25 g. of sodium hydroxide in 200 ml. of water at 0 C. After minutes the deep blue solution was acidified with 1 N. hydrochloric acid. The solid which separated was collected and vacuum dried, yielding 25 g. of product, M.P. 280 C.

DYE 2 To a solution of 4.7 g. of 4,4-diaminobenzil in a mixture of 10 ml. of concentrated hydrochloric acid and 100 ml. of water was added at 0 C. over a period of 30 min utes with stirring a solution of 2.8 g. of sodium nitrite in 25 ml. of water. H

To this diazonium solution was added a solution of 7.5 g. of 1-hydroxy-2-naphthoic acid in 200 ml. of pyridine at 0 C. The resultant dark red solution was evaporated overnight, after which time the residual paste was slurried in 500 ml. of water. The solid was collected, vacuum dried and recrystallized from acetic acid, yielding 6 g. of product, M.P. 200 C. (decomposes).

DYE 3 To the diazonium solution of 4.7 g. of 4,4'-diamino benzil (prepared as for Dye 2) was added a solution of 10.3 g. of 1-(4-sulfophenyl)-3-h1ethyl-5-pyrazolone and 10 g. of sodium acetate in 100 m1. of 50% acetic acid at 10 C. The reaction mixture was stirred at room temperature for 2 hours, after which time it was concentrated in vacuo to dryness. The crude solid was recrystallized from 70% acetic .acid, yielding 3.6 g. of product, M.P. 290 C.

DYE 4 To the diazonium solution of 4.7 g. of 4,4-diamino benzil (prepared as described) was added a solution of 7 g. of 1-pheny1-3-methyl-5-pyrazolone and 10 g. of sodium acetate in 100 ml. of 50% acetic acid at 10 C. The reaction mixture was stirred at room temperature for one hour, after which time the precipitate which had separated 6'1 was collected and dried, yielding 11 g. of product, M.P. 290 C.

DYE s u.-Ketononadecanoic acid (prepared as described in Compt. Rend, vol. 202, 1523 (1936)) is converted to a acetoxynonadecanoic acid by reaction with acetic anhydride, and then converted to the corresponding acid chloride by reacting it with thionyl chloride. The u-acetoxynonadecanoyl chloride is reacted with acetanilide in a Friedel-Crafts reaction with aluminum chloride catalyst and the product is hydrolyzed to produce 1-(4-aminophenyl)-1,2-nonadecane dione. The 1-(4-aminophenyl)-1,2- nonadecane dione is reacted with l-hydroxy-Z-naphthoyl chloride and the resulting compound is then reacted with the oxidized form of 4-[N-ethyl-N(fi-hydroxyethyl)]- aminoaniline to produce Dye 5.

DYE 6 1-(4-aminophenyl)-1,2-nonadecane dione prepared as described for Dye 5 is diazotized with isoamylnitrite in npropanol in the presence of p-toluene sulfonic acid monohydrate and the resulting diozonium compound is reacted with OL-HaPhthO]. dissolved in pyridine to produce Dye 6.

DYE7

To the diazonium solution of 4.7 g. of 4,4'-diaminobenzil (prepared as in No. 2 above) was added a solution of 15 g. of H acid and 25 g. of sodium carbonate in 250 ml. 'of water at 5 C. The reaction mixture was stirred at room temperature for 2 hours and evaporated overnight. The crude residual solid was recrystallized from 50% ethyl alcohol, yielding 10 g. of product, M.P. 280 C.

The non-silver light-sensitive elements of my invention are valuable for the direct production of dye positive images by a very simple and short process. When desired a dye negative image can also be produced by transferring the ditr'usible dye image produced by the imagewise splitting of the a-diketone group which releases ballast from the otherwise nondiffusible dye. Use of my light-sensitive elements eliminates the complex and lengthy processes required to produce color reproductions with many of the prior art elements.

The invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. A light-sensitive color photographic element comprising a support having coated thereon at least one layer comprising:

(1) a hydrophilic colloid;

(2) an inorganic semiconductor selected from the class consisting of compounds of zinc, titanium, gallium and cadmium, such that the said semiconductor which in the presence of moisture and oxygen causes hydrogen peroxide to be formed upon irradiation by light in proportion to the amount of irradiation; and

(3) an open chain u-diketone dye that is nondiifusible in said hydrophilic colloid.

2. A light-sensitive color photographic element comprising a support having coated thereon at least one layer comprising:

(1) a hydrophilic colloid;

(2) a semiconductor selected from the class consisting of zinc oxide, titanium dioxide, cadmium sulfide, gallium nitride, and cadmium selenide; and

(3) an open chain u-diketone dye that is nondifiusible in said hydrophilic colloid.

3. A light-sensitive color photographic element comprising a support having coated thereon at least one layer comprising:

(1) a hydrophilic colloid;

(2) a semiconductor selected from the class consisting of zinc oxide, titanium dioxide, cadmium sulfide, gallium nitride, and cadmium selenide; and

(3) a dye image-forming compound having the forrnula:

wherein W represents an organic dye selected from the class consisting of an azo dye, a triphenylmethane dye, a methine dye, an indoaniline dye, an indophenol dye, an azomethine dye, and an anthraquinone dye; Y represents an alkyl group having from 10 to 22 carbon atoms; and n represents an integer of from to 1.

4. A light-sensitive color photographic element of claim 3 in which W in said dye represents an azo dye.

5. A light-sensitive color photographic element of claim 3 in which the said dye is 4,4'-bis(1-hydroxy-4- naphthylazo)benzil.

6. A light-sensitive color photographic element of claim 3 in which the said dye is 4,4-bis(1-hydroxy-2- carboxy-4-naphthylazo)benzil.

7. A light-sensitive color photographic element of claim 3 in which the said dye is 4,4-bis(l-p-sulfophenyl- 3-methyl-5-pyrazolyl-4-azo)benzil.

8. A light-sensitive color photographic element in claim 3 in which the said dye is 4,4-bis(1-phenyl-3- methyl-5-pyrazolyl-4-azo)benzil.

9. A light-sensitive color photographic element of claim 3 in which the said dye is 1-oxo-4-{4-[N-ethyl-N- 3-hydroxyethyl)-phenyl]imino} 4' stearoylcarbonyl- 2-naphthanilide.

10. A light-sensitive color photographic element comprising a support having coated thereon a light-sensitive layer comprising polyvinyl alcohol, zinc oxide and 4,4- bis( 1-hydroxy-4-naphthylazo)benzil.

11. A light-sensitive color photographic element comprising a support having coated thereon a light-sensitive layer comprising polyvinyl alcohol, Zinc oxide, and 4,4- bis 1-hydroxy-2-carboxy-4-naphthylazo benzil.

12. A light-sensitive color photographic element comprising a support having coated thereon a light-sensitive layer comprising polyvinyl alcohol, zinc oxide, and 4,4 bis(1 p sulfonphenyl-3-methyl-5-pyrazolyl-4- azo)benzil.

13. A light-sensitive color photographic element comprising a support having coated thereon a light-sensitive layer comprising polyvinyl alcohol, zinc oxide, and 4,4- bis( l-phenyl-3 -methyl-5-pyrazolyl-4-azo benzil.

14. A light-sensitive color photographic element comprising a support having coated thereon a light-sensitive layer comprising polyvinyl alcohol, zinc oxide, and l-oxo- 4-{4-[N-ethyl N (fl-hydroxyethyl)phenyl]imino}4- stearoylcarbonyl-2-naphthanilide.

15. A photographic process for producing a direct positive dye image comprising the steps of:

(1) soaking in water a color photographic element comprising a support having coated thereon a lightsensitive layer comprising;

(a) a hydrophilic colloid,

(b) a semiconductor selected from the class consisting of zinc oxide, titanium dioxide, cadmium sulfide, gallium nitride and cadmium selenide, and

(c) an open chain u-diketone dye that is nondifiusible in said hydrophilic colloid;

(2) exposing said water soaked element to activating light from an original image; and

(3) washing said image exposed element with water to leave a direct dye positive image reproduction of said original image said positive image being formed by the said open chain a-diketone dye.

16. The process of claim 15 in which the color photographic element is soaked before image exposure in water containing suificient hydroxyl ions to produce a pH of 13.

17. The process of claim 15 in which the color photographic element is soaked before image exposure in water containing suflicient hydroxyl ions to produce a pH of 13, and after image exposure is washed in a dilute acid solution.

18. A photographic process for producing a direct positive dye image and a direct negative dye image comprising the steps of:

(1) soaking in Water a color photographic element comprising a support having coated thereon a lightsensitive layer comprising:

(a) a hydrophilic colloid,

(b) a semiconductor selected from the class consisting of zinc oxide, titanium dioxide, cadmium sulfide, gallium nitride and cadmium selenide, and

(c) an open chain a-diketone dye that is nondiifusible in said hydrophilic colloid;

(2) exposing said water soaked element to activating light from an original image;

(3) contacting said exposed water soaked element with a receiving sheet containing a cationic mordant to transfer the diifusible dye image to the receiving sheet; and then (4) separating the said receiving sheet with its dye negative image from the said element with its dye positive image.

19. The process of claim 18 in which the said color photographic element is soaked before image exposure in water containing sufficient hydroxyl ions to produce a pH of 13.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES Fukushima et al.; Soc. of Chem. Ind. of Japan, vol. 35, 1932, pages 39813-3993 NORMAN G. TORCHIN, Primary Examiner. 

18. A PHOTOGRAPHIC PROCESS FOR PRODUCING A DIRECT POSITIVE DYE IMATE AND A DIRECT NEGATIVE DYE IMAGE COMPRISING THE STEPS OF: (1) SOAKING IN WATER A COLOR PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING COATED THEREON A LIGHTSENSITIVE LAYER COMPRISING: (A) A HYDROPHILIC COLLOID, (B) A SEMICONDUCTOR SELECTED FROM THE CLASS CONSISTING OF ZINC OXIDE, TITANIUM DIOXIDE, CADMIUM SULFIDE, GALLIUM NITRIDE AND CADMIUM SELENIDE, AND (C) AN OPEN CHAIN A-DIKETONE DYE THAT IS NONDIFFUSIBLE IN SAID HYDROPHILIC COLLOID; (2) EXPOSING SAID WATER SOAKED ELEMENT TO ACTIVATING LIGHT FROM AN ORIGINAL IMAGE; (3) CONTACTING SAID EXPOSED WATER SOAKED ELEMENT WITH A RECEIVING SHEET CONTAINING A CATIONIC MORDANT TO TRANSFER THE DIFFUSIBLE DYE IMAGE TO THE RECEIVING SHEET; AND THEN (4) SEPARATING THE SAID RECEIVING SHEET WITH ITS DYE NEGATIVE IMAGE FROM THE SAID ELEMENT WITH ITS DYE POSITIVE IMAGE. 